#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
  int b = 0, k = 0;
  char c;
  while ((c = getchar()) != EOF) {
    if (c == 'b') {
      b++;
    }
    if (c == 'k') {
      k++;
    }

  }
  if (b > k) {
    printf("boba\n");
  } else if (k > b) {
    printf("kiki\n");
  } else if (k == 0 && b == 0) {
    printf("none\n");
  } else if (k == b) {
    printf("boki\n");
  }
  return 0;
}